This study aims to determine how flywheel-based inertial training (FIT) implemented according to principles of velocity-based training (VBT) and High-Intensity Interval Training (HIIT) affects disuse-induced physical de-conditioning including loss of voluntary muscle strength, aerobic capacity, and balance regulation.
This study will characterize intramuscular molecular mechanisms underlying anabolic resistance to protein ingestion during muscle disuse. Adults (n=12) will be studied using a unilateral leg immobilization model in which one leg will be randomly assigned to immobilization and the contralateral, active leg used as a within-subjects control. Immobilization will be implemented for five days using a rigid knee brace, during which time participants will ambulate using crutches. Integrated ribonucleic acid (RNA) synthesis will be determined during immobilization in the immobilized and non-immobilized legs using ingested deuterium oxide, salivary and blood sampling, and muscle biopsies. Immediately after immobilization, muscle biopsies will be collected before and 90 mins after consuming 25 g of whey protein from the immobilized and non-immobilized legs to characterize the intramuscular molecular response to protein feeding. Serial blood samples will be collected during that time to characterize the circulating metabolic response to protein ingestion. Knowledge generated from this effort will inform the development of targeted interventions for mitigating anabolic resistance to protein ingestion that develops during periods of muscle disuse.
This project is a 2-phase, randomized clinical trial that includes 7 days of unilateral leg disuse (Phase 1), immediately followed by 1 week of bilateral leg rehabilitation (Phase 2). The investigators will recruit cohorts of healthy middle-aged men and women to address their aims: * Demonstrate the sex-specific effects of skeletal muscle disuse (Phase 1) * Identify key molecular determinates of susceptibility of skeletal muscle atrophy (Phase 1) * Map the early, sex-specific molecular time-course of rehabilitation (Phase 2) * Determine if disused and healthy muscle respond similarly to exercise (Phase 2) Healthy, middle-age men and post-menopausal women (50-65 years) will be recruited from the greater Houston/Galveston area. This under-represented research demographic demonstrate few negative metabolic or phenotypic signs of advanced age, but are at increased risk of being hospitalized and experiencing accelerated loss of lean mass and muscle function that parallels a much older population. The goal of this study is to characterize phenotypic and molecular skeletal muscle changes in middle-aged men and women during critical periods of disuse and rehabilitation and ultimately direct the development of targeted and effective prevention and treatment strategies.
The purpose of this study is to define the effects of chronic disuse on skeletal muscle structure and function in elderly individuals at the cellular and molecular level by examining elderly characterized by chronic muscle disuse (patients with knee osteoarthritis) and healthy elderly no evidence of knee osteoarthritis and normal physical activity levels.
Individuals who sustain musculoskeletal injuries (MSKI) can experience a rapid loss of muscle mass due to declines in muscle loading and activation that occur post-injury (i.e., disuse atrophy). Loss of muscle under these conditions is attributed to a persistent negative net muscle protein balance (muscle protein synthesis \[MPS\] \< muscle protein breakdown) that results, in part, from declines in postprandial MPS (i.e., anabolic resistance). Nutritional interventions that enhance postprandial MPS may be used to overcome disuse-induced anabolic resistance and preserve muscle mass to accelerate recovery and improve recovery outcomes. While supplemental protein has been explored as a potential countermeasure to disuse-induce anabolic resistance, the observed efficacy of such interventions has been mixed. Equivocal findings across studies may be attributed, in part, to an insufficient understanding of what constitutes an effective protein-based intervention. Importantly, no study to date has determined an optimal protein dose for overcoming disuse-induce anabolic resistance, or if there is a threshold for maximally stimulating postprandial MPS under disuse conditions. Therefore, the objective of this work is to determine rates of MPS at rest and in response to standard (20 g) or high (40 g) doses of whey protein during knee immobilization (DISUSE) compared with standard activity (ACTIVE)
This project aims to determine whether a novel strength training rehabilitation protocol can diminish the negative consequences of limb immobilization and expedite the restoration of muscle function during retraining in healthy individuals.
This is an interventional study enrolling healthy individuals aged 18-35 and 60-85 to understand the recovery of muscle health following a period of inactivity. The enrollment goal is 45 participants. The study will occur over the course of 1-2 months where participants will undergo testing before and after a 2-week limb immobilization period.
Clinical trial The goal of this clinical trial is to learn how muscle weakness and atrophy develop during short periods of arm immobilization and whether a type of exercise called cross-education can help reduce these effects in women at midlife. The main questions it aims to answer are: What changes happen in the nervous system that lead to weakness when a wrist is immobilized? Can training the opposite arm help maintain muscle strength, muscle size, and nervous system function in the immobilized arm? Researchers will compare women who have their wrist immobilized with or without opposite-arm resistance training. Participants will: Wear a wrist cast on one arm for 7 days Complete strength training with the opposite arm or no training, depending on their group Attend study visits for strength and nervous system testing Have non-invasive tests (like magnetic brain stimulation, muscle recordings, and muscle imaging) to measure how the nervous system and muscle responds
The investigators aim to study the use of blood flow restriction therapy (BFR) to augment routine post-operative physical therapy in elderly patients (age \>= 65) after recovering from surgical treatment of hip fractures.
The primary objective of this study is to determine whether muscle atrophy induced by immobilization of the lower limb can be attenuated by BIIB023 in healthy male volunteers. The secondary objectives of this study in this study population are: * To determine whether muscle weakness induced by immobilization of the lower limb can be attenuated by BIIB023 * To assess the effect of BIIB023 on the recovery of muscle mass and strength after immobilization * To assess the effect of BIIB023 on histological markers of muscle atrophy and regeneration * To assess the effect of BIIB023 on muscle bioenergetics based on oxidative metabolism recovery kinetics * To evaluate the safety and tolerability of BIIB023